Oil compositions containing metal salt of phenol and low molecular weight acid



United States Patent OIL COMPOSITIONS CONTAINING METAL SALT XgISI-IENOL AND LOW MOLECULAR WEIGHT Arnold J. Morway, Clark, and John C. Munday, Cranford, N.J., assignor's to Esso Research and Engineering Company, a corporation of Delaware N0 Drawing. Filed Mar. 1, 1961, Ser. No. 92,453 13 Claims. (Cl. 25233.6)

This invention relates to compositions comprising the metal salt of phenol and low molecular weight acid, to oil solutions and dispersions of said salt, and to methods for their preparation.

This application is a continuation-in-part of our copending application, Serial No. 803,374, now Patent No. 3,065,179, filed April 1, 1959.

The salt compositions of this invention can be used in lubricating oil to form fluid lubricants having high load carrying ability and giving reduced wear. They can also be used in lubricating greases as thickeners, extreme pressure agents, and anti-wear additives. Another use of the salts is in the formation of hydrocarbon oils used as oil fracturing fluids.

In general, the additives of this invention will be prepared by coneutralizing a phenol and a low molecular weight acid with a metal base, or by reacting the metal base with the acid to form a salt and then heating the salt and the phenol until dehydrated, or until any free low molecular weight acid evolved is removed. The mole ratio of the low molecular weight acid to phenol will be greater than 3 to l. Mole ratios of the acid to phenol in the range of 5/1 to 40/ l are preferred for preparation of lubricants because they impart greater extreme pressure and anti-wear properties. However, in the case of phenols alkylated with very long chain polymers, mole ratios up to 300/1, or more, are possible.

The metal component of the salts of this invention is a polyvalent metal. Included are polyvalent metals of groups II-A, lL-B, III-A, IV-B and VIII of the periodic table. Diand tri-valent metals are preferred. The alkaline earth metals, and especially calcium are particularly preferred in forming lubricants because of the better properties obtained. Examples of the metals included within the invention are barium, chromium, cadmium, nickel, iron, cobalt, calcium, zinc, and aluminum. Mixtures of these metals may be employed if desired. The metals are usually reacted with the acid, or acid and phenol mixture, in the form of hydroxides and oxides, but other bases such as the carbonates, etc. may be used. Sufficient metal base is used to substantially neutralize the acid and phenol. In general, this will require a slight excess of the metal base to insure complete neutralization.

Low molecular weight monocarboxylic acids having about 2 carbon atoms per molecule are used as the acid component. The preferred acid for use in accordance with the present invention is acetic acid or its anhydride. The term acid as used herein, will include anhydrides where available. Substituted acetic acids may also be used. These substituted acetic acids include glycolic acid or hydroxy-acetic acid, thioglycolic acid or mercaptoacetic acid, monochloro-acetic acid, dichloro-acetic acid, trichloro-aetic acid and the corresponding bromo andfiuoro acetic acids, and mixtures of these acids with and without acetic acid.

Mixtures of acetic acid or its derivatives with other organic and inorganic acids may also be used. In this case, the molar amount of said other acids should be less than that of acetic acid or its derivatives. The other organic acids include oxalic acid, propionic acid, acrylic 3,l30,lb0 Patented Apr. 21, 1964 acid, and benzene, toluene and xylene sulfonic acids, etc. The inorganic acids include carbonic, hydrochloric, nitric, sulfuric and phosphoric acids, etc.

The generic formula for the acetic and substituted acetic acids to be used in accordance with the present invention is as follows: Y .CH .COOH, wherein n is a digit from 0 to 3 inclusive and Y is a monovalent substituent selected from the group consisting of hydroxyl (-OH), mercapto (--SH) and halogen substituents such as (-Cl), (F) or (Br). When Y=OH or SH, 11 must equal 1.

Phenols useful in the preparation of the compositions of this invention can be defined by the following formula:

wherein n is 0 to 4, and R is selected from the group consisting of C to C alkyl groups, C to C alkyl amino groups, C to C alkyl phenol groups and polymers of C to C monoolefin-l, said polymers having molecular weights of 500 to 20,000, preferably 1,000 to 5,000. Specific examples of the alkyl phenols are cresol, xylenol, S-amyl phenol, isooctyl phenol, triisopropyl phenol and triisobutyl phenol. Specific examples of those compounds wherein R represents an alkyl amino group are: 2,6-ditertiary butyl-4 (dimethyl amino methyl) phenol, 2-methyl-4-(di-n-butyl amino methyl) phenol and m-di-rnethylamino phenol. The term alkyl amino as used herein includes compounds wherein the amino group is directly attached to the aromatic nucleus, as well as compounds wherein the amino group is separated from the aromatic nucleus by one or more carbon atoms. An example of a compound wherein R is an alkyl phenol group, is p,p-isopropylidene diphenol, which is commercially available under the trade name Bisphenol A. Examples of the polymers are polyisobutylene, poly-noctylene, copolymers of isobutylene and piperylene, etc.

' Various mixtures of the above phenols may also be used.

A particularly preferred mixture is the mixture of cresol and xylenols found in tar acids.

An economical source of unsubstituted phenol, is the phenol extract obtained by extraction of various mineral lubricating oil fractions. Thus, it is a common practice to form high viscosity index lubricating oils by solvent extracting the oil with phenol (sometimes in the presence of a small amount of water). The phenol dissolves out aromatics which are present in the oil being treated, and is decanted. Usually, the aromatics are later separated from'the phenol, so that the phenol can be recycled and used again. However, the phenol extract per se (i.e. the phenol and aromatics) can be used in the present invention both as a source of phenol and as a source of lubricating oil (i.e. the aromatics).

As previously indicated, the compositions of this invention may be prepared by several methods. One method is by coneutralizing, preferably in situ in at least a portion of the hydrocarbon, the phenol and low molecular weight acid with the metal base. This can be followed by heating to dehydrate the product, or alternatively the water of reaction may be left in the product, and no external heating is applied. Another technique is by reacting the acid with the metal base to form a salt, and then heating the salt with the phenol to remove water of reaction or liberated free acid. In this latter technique, excess metal base is best used to form the salt, so that metal base is also available for reaction with the phenol. Usually, but not necessarily, all methods indicated above are carried out in an oil menstruum. Heating of the reaction mixture if done at all, may be Li carried out at temperatures in the range of about 180 to 600 F., and preferably about 300 to 450 F.

The preferred embodiment of this invention when a lubricant is desired, is to thoroughly mix acetic acid and a phenol in a lubricating oil and then add a substantially stoichiometric amount of metal base, followed by heating to dehydrating temperatures in the range of about 250 to 550 F. Dehydration time will depend on temperature and batch size and hence is Widely variable, however, the time will generally range from 15 minutes to 12 hours, e.g., about /2 hr. to 6 hours. The composition is then cooled to about 180 to 200 F. at which temperatures conventional lubricant additives, if desired, can be added. The mixture may then be homogenized such as by passing through a Gaulin hom-ogenizer or a Charlotte miil, followed by subsequent cooling to room temperatures.

When the final product is intended for an oil well fracturing fluid, then it is generally more economical not to heat. These fracturing fluids are generally used by forcing the fluid down an oil well under high pressure, while simultaneously adding sand. The fluid seeps into fissures in the rock and actually opens up or cracks the rock as it attempts to expand in the fissures, thus in turn creating new fissures. The fluid of the invention is quite effective in suspending the sand, which in turn is deposited in the fissures. The deposited sand, then prevents closure or clogging of these fissures once pressure is released and the treatment discontinued. The oil can then flow more readily through the opened fissues to the well casing.

Where the compositions of this invention are prepared in an oil menstruum, the oil can be either a mineral or an inert synthetic oil having a viscosity at 100 F. in the range of 60 to 3000 SSU. Mineral oils having a viscosity at 100 F. in the range of 100 to 1200 SSU are particularly preferred. Any inert synthetic lubricating oils meeting the above viscosity requirements may be used. These synthetic oils include poly silicones, the simple and complex ester-type oils, the alkyl silicates, etc.

The compositions of this invention can include various other additives. Such additives include: metal salts such as calcium petroleum sulfonate, and alkali and alkaline earth metal soaps of C to C fatty acids; oxidation inhibitors such as phenyl a-naphthylamine; viscosity index improvers such as polyisobutylene; pour depressants; dyes and other conventional lubricant additives. Some of the conventional additives, such as sulfonates, fatty acid soaps, polyglycols, etc. can be present during the preparation of the metal salts of this invention to also serve as dispersing agents. When fatty acid soaps are employed with the compositions of this invention in lubricating oils, the soaps will comprise about 0.5 to weight percent of the total compositions.

The metal salt compositions of this invention when used as additives in fluid lubricants, preferably lubricants having a viscosity in the range of 100 to 1200 SSU at 100 R, will comprise about 0.2 to 20 Weight percent of the total composition. When the metal salts of this invention are used as thickeners to form lubricating greases they will comprise about to 40 weight percent of the total composition. The shorter the alkyl chain (i.e. the smaller the number of carbon atoms in the alkyl group) attached to the phenolic radical the greater the thickening power of the resultant metal salt composition. Thus, smaller weight percentages of the compositions of this invention which contain short alkyl chains upon the phenolic radical are required to thicken a lubricating oil to a grease consistency.

When used in fracturing fluids, the salts are used in concentrations of 0.001 to 1.0 wt. percent, preferably 0.01 to 0.10 wt. percent. The fracturing fluids are best prepared by first making a grease-like concentrate of the salts and then drastically diluting with low grade inexpensive mineral oil to form the fracturing fluid.

The invention will be further understood by the following examples which include the preferred embodiments of this invention.

Properties Opaque, fluid lubricant.

Preparati0n.-The lime and oil were mixed intimately with heating. The phenol and acetic acid were added and the mixture heated to about 300 F. with continued agitation until evolution of gas (water vapor) stopped.

EXAMPLE II Table 11 gives the weight percent composition and properties of excellent lubricating greases prepared by coneutralizing the phenol and acetic acid in mineral oil with hydrated lime (calcium hydroxide).

Preparatl'0n.-The compositions of Table II were prepared by charging hydrated lime and mineral oil of 55 SUS viscosity at 210 F. to a grease kettle and intimately mixing. The phenolic compound and acetic acid were blended and the blend charged to the lime and mineral oil slurry with continued mixing at a temperature of about to 180 F. Heating was then continued until the temperature of the reaction mixture reached about 320 F. This temperature was maintained for about 15 minutes whereupon the temperature Was lowered to 200 F. and phenyl a-naphthylamine was added as an oxidation inhibitor. The greases were next Morehouse milled at between to 200 F. and 0.004" clearance.

Table II Greases Composition, Wt. Percent:

Glacial Acetic Acid 15. 0 15.0 15.0 p-Oresol 4.0 Mixed Cresols 4. 0 Xylenol 2 4. 0 Hydrated Lime 11 5 11.0 11.5 Phenyl a-Naphthylamine 1. 0 1. 0 1. 0 Mineral Oil (55 SSU 210 F.) 68. 5 69.0 68. 5 M01 Ratio, Acid/Phenol 6. 8 7.6 6. 8 Properties:

Dropping Point, F 500+ 500+ 500+ Penetration, 77 F., mrn./10-

Unworked 398 320 350 Worked, 60 Strokes 325 325 335 Worked, 10,000 Strokes. 321 325 345 Water Solubility (Boiling Water) Insoluble Insoluble Insoluble 4-Ball Wear Test Scar Diam., mm. (1,800 r.p.m.10 Kg. Load 75 C. for 1 Hr.) 0. 21 0. 26 0. 24 Lubrication Life Hours 10,000

r.p.m. 250 F. 2, 000+ 2, 000+ 2, 000+ Timken Test (43 lbs. load) Pass Pass Almen Test (Wts. carried with excellent pin condition)- Gradual Loading, 15 wt.

max Pass Pass Shock Loading, 15 Wt. max Pass Pass l 54 wt. percent m-cresol, 29 wt. percent p-crcsol and about 17 wt. percent of o-cresols and xylenols.

4,5-dimethyl phenol.

3 Test discontinued after 2,000 hours.

As shown in Table II the greases prepared by concutralizing acetic acid and cresols, xylenols and mixtures of the two in a mineral oil base have excellent extreme pressure and anti-Wear properties. The greases prepared in this manner are also highly important in that they are formed at temperatures within the range of conventional steam heated grease kettles and in that they may be blended with additional lubricating oil to form liquid concentrate lubricating oil additives.

Excellent greases and additive compositions are also prepared by substituting for the mineral oil base and hydrated lime a synthetic ester oil of lubricating oil viscosity and a metal hydroxide selected from the group consisting of barium, chromium, cadmium, nickel, cobalt, iron, Zinc and aluminum hydroxides.

EXAMPLE III 0 M 2,6 ditertiary butyl-4-(N,N-dimethy1-aminomethyl)phenol Preparation.-T he mineral oil, lime and Hydrofol acids (commercial mixture of fatty acids equivalent to stearic acid) was charged to a heated grease kettle and intimately mixed. To this mixture was charged the alkylated amino phenol dissolved in the acetic acid at 130 F. Heating was initiated after the heat of the reaction had subsided and the temperature raised to 410 F. The product was cooled rapidly and then milled by passage through a Morehouse mill having a clearance of 0.003.

The composition in terms of weight percent and the properties of the resultant grease are given in Table 111.

Worked 60 strokes 2 67. Worked 10,000 strokes- 332. Wheel bearing test, 220 F. Pass. 400 -F. beaker test or softenfexcessively on either the beating or. cooling cycle.

Water solubility '(boiling water) Lubrication life hours, 250

F.-10,000 r.p.m 1896. Timken test (45 lbs. load) Pass.

1 2,6 ditertiary butyl (N,N dimethyl aminomethyl)- phenol.

Insoluble.

The above example shows the preparation of excellent high temperature, extreme pressure and wear-resistant greases wherein an alkylated amino phenol is substituted for the alkyl phenol. The example also showsthe use of fatty acid soaps in the greases of this invention and particularly the addition of the fatty acid soap to the No tendency to fluidize EXAMPLE 1V An alkylated phenol was prepared by standard alkylation techniques utilizing a polyisobutylene of about 1100 molecular weight. The phenol material was prepared as follows:

500 grams of the polyisobutylene was dissolved in 500 cc. of n-heptane and 50 grams of phenol in a BF .complex were added. The resulting mixture was heated to 90 to 95 F. for three hours. The material was then cooled, washed with water, decanted and then distilled at a pressure of about 10 mm. Hg to remove the solvent and excess phenol. The resulting residue of the isobutylene-phenol totaled 228 grams having an hydroxyl number of 106.9 and an oxygen content of 3.18 wt. percent.

A grease utilizing the residue obtained above was prepared as follows:

Lime, the phenol treated polybutylene and mineral oil were charged to a steam heated kettle and thoroughly mixed. Next, acetic anhydride was slowly added while stirring and a brisk reaction occurred with the temperature rising to 220 F. The material was then heated to 320 F. until the product was dehydrated, following which phenyl-alpha-naphthylamine was added as an antioxidant. Next the material was cooled to about 110 F. at which point it was homogenized by passing through a Gaulin homogenizer at 6,000 p.s.i.

EXAMPLE V Phenol was treated with a copolymer of piperylene and isobutylene as follows:

500 grams of the copolymer was dissolved in 500 ml. of n-heptane. 50 grams of phenol in a BF complex were added and the reaction occurred at 100 C. while heating for 3 hours. The product was cooled and washed with water. The solvent and phenol employed in excess were removed by distillation under reduced pressure. The piperylene and polyisobutylene copolymer had a molecular weight of about 3000 and consisted of about equimolar amounts of piperylene and isobutylene.

A grease was prepared using the above alkylated phenol in the same general manner as that of Example IV.

The compositions and properties of the materials of Examples IV and V are summarized in Table N which follows:

Table IV Examples IV V Composition (Wt. percent):

Acetic Anhydride Phenol treated polybutylene. Phenol treated copolymer of piperylene and isobutylene. Hydrated lime Phenyl a-naphthylamine. 1 0 Mineral Lubricating Oil of SUS at 210 F. Properties:

Appearance Excellent fluid Excellent fluid homogeneous. homogeneous. Stability No sedimentation No sedimentation after standing over 6 months storage. Timken.Test

lbs.-Narrow scar-.- Pass. lbs.-Narrowsear-.- Fail. Gear Testln hypoid No wear.

gears for 6 months.

EXAMPLE VI-A A lubricant was prepared lltlllZlIlg. a phenol extract containing 5.5 wt. percent phenol and obtained by treat- 7 8 ing a coastal type mineral lubricating oil having a vis In sum, the invention comprises oil dispersions of cosity of 500 SSU at 100 F. and a viscosity index of polyvalent metal salt of a C monocarboxylic acid and a 40 with 500 Wt. percent phen lphenol. In general, the compositions are preferably pre- 11.5 wt. percent of hydrated lime was added to 73.5 pared by coneutralizing 3 to 35 wt. percent of the C acid wt. percent of the phenol extract described above and 5 and 0.5 to wt. percent of the phenol, in situ in oil, said mixed, following which 15.0 wt. percent of glacial acetic wt. percent being based on the total Weight of the ingreacid was slowly added without external heating. The dients. The resulting composition may then be diluted to temperature rose to 180 F. during the addition of acetic give the desired overall salt concentration. Other techacid, and stirring Was Continued for another One-half niques can be employed as previously discussed, as well hour. The product was then passed through a Mor 10 as other proportions which are less preferred.

house mill having 0.003" clearance. The resulting mate- Wh t i l i d i rial was an excellent smooth grease-like product having 1, An il composition comprising a major proportion ASTM Penetrations (1111111 as follows: of oil and alkaline earth metal salt prepared by coneu- UHW0fk6d295 Worked 6O Stf0ke$-320 tralizing with alkaline earth metal base, about 0.5 to 10 and Worked 10,000 Strokes-430 Wt. percent of about 0.5 to 10 wt. percent of phenol and EXAMPLE about 3 to 35 wt. percent of low molecular weight monocarboxylic acid having about 2 carbon atoms per mole- 0.5 wt. percent of the product of VIA above was Cule, wherein Said phenol has the formula; mixed with 99.5 wt. percent of a mineral lubricating oil OH having a viscosity of 70 SSU at 100 F. The resulting product was a uniform homogeneous opaque suspension showing no tendency to separate over long period of time 7 (R5 and which was suitable as an oil well-fracturing fluid.

EXAMPLE VII where n is 0 to 4, and R is selected from the group con- A. Hydrated lime was intimately mixed with mineral Sisting of 1 to 24 alkyl r ps, C to C alkyl amino oil in a grease kettle. Next, a blend of acetic acid and groups: 7 to 23 alkyl Phenol groups and Polymeric mixed cresols was added and the heat of reaction ingroups 500 to 20 000 molecular Weight P p e y creased the temperature to about 250 F. The mixture polymelflzmg a to 24 1110000161334, f Whefelll the was then allowed to 6001, While Stirring, to room mol ratio of said acid to said phenol is between about perature and was then homogenized in a Manton-Gaulin 5:1 to 30011- homogenizer at 5,000 p.s.i. The mixed cresols consisted composltlon accoldlng 9 Claim 1, ntalningufl of about 5 52 Wt percent nun-e501, about 18 2Q Wt, addition thereto, 0.5 to 5.0 weight percent of alkallne percent p-cresol, about 2-3 Wt. percent o-cresol and the earth n}eta1 Salt of a high molecular Weight fatty acid b l was l L contalning 12 to 30 carbon atoms per molecule.

B. 0.5 wt. percent of the product of A above was A composition to 6181111 wherein i mixed together with 99.5 wt. percent of a mineral lubri- 011 15 a mlneral lubrlcatlng 011 having 21 Viscosity in the eating oil having a viscosity of 80 SUS at 210 F., folrange of 100 to 1200 SSU at and wherein h l d by h i ti i a M t G 1i h mol ratio of said acid to said phenol is in the range of genizer operating at 3,000 p.s.i. 40 511 t0 4011- C. and E. Two more lubricants were prepared in the A Composltlon according to claim wherein R i same general manner as that of A above, except that anisobutylene P- difi t materials were ili d 5. A composition according to claim 1, wherein R is D. and F. Lubricants D and F were prepared by a copolymel'ic group consisting of P p y and diluting the compositions of C and E, respectively, in the butyleflesame manner that product B was prepared by diluting A COIHPOSIUOII aCcofdlllg t0 Clalm wherein a d product A. phenol is cresol.

Th Compositions of d t A to F, i terms f th i 7. A composition according to claim 1, wherein said ingredients, and their physical properties are summarized P ol 1S dodecylphenol. in Table VII which follow 8. A composition according to claim 1, wherein n is 0.

Table VII Example VII Composition (Wt. Percent):

Glacial Acetic Acid 0.75.

Appearance Dropping Point, F

Penetration, 77 F., m

Unworked. Worked, Strokes Worked, 10,000 Strokes- Water Solubility (Boiling ater Wheel Bearing Test Excellent. fluid.

1 Trade name for p,p-isopr0py1idine diphenol.

As illustrated by the previous table, excellent greases 9. A composition according to claim 1, wherein said can be prepared as illustrated bycompositions A, C and phenol is 2,6-ditertiary butyl-4-(N,N-dimethylamino- E, or these grease materials can be drastically diluted methyl) phenol. with additional oil to form fluids which are suitable for 10. A composition according to claim 1, wherein said oil fracturing use. phenol is p,p'-isopropylidene diphenol.

wherein R represents a C to C alkyl group, in a mol ratio of said acid to said phenol of 5:1 to 40:1, and wherein said alkaline earth metal salts are prepared by coneutralizing said acetic acid and said phenol with alkaline earth metal base.

12. A method which comprises neutralizing in a major amount of mineral oil with alkaline earth metal base, about 0.5 to 1 0 wt. percent of a phenol and about 3 to 35 wt. percent of acetic acid to thereby form alkaline earth metal salt of said acetic acid and said phenol, wherein said phenol has the formula:

where n is 0 to 4 and R is selected from the group consisting of C to C alkyl groups, C to C alkyl amino groups, C to C alkyl phenol groups and polymeric groups of 500 to 20,000 molecular weight prepared by polymerizing C to C monoolefin-l, and wherein the mol ratio of said acetic acid to said phenol is within the range of about 3:1 to 300:1.

13. A method according to claim 12, wherein said mineral oil is a mineral lubricating oil, said alkaline earth metal base is lime, and said mol ratio of said acetic acid to said phenol is about 5:1 to :1.

Bell Sept. 3, 1957 Martinek Aug. 12, 1958 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No 3 130 160 April 21, 1964 Arnold Ju Morway et aln hat error appears in the above numbered pat- It is hereby certified. t

that the said Letters Patent should read as ent requiring correction and corrected below.

Column 8, line 15 strike out "about 005 to 10 wt percent of".

Signed and sealed this 27th day of October 1964.

(SEAL) Attest:

EDWARD J. BRENNER ERNEST W. SWIDER' Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 130 160 April 21 1964 Arnold J, Morway et alu the above numbered pat- It is hereby certified that error appears in s Patent should read as ent requiring correction and that the said Letter corrected below.

Column 8, line 15 strike out "about 005 to 10 wt percent of".

Signed and sealed this 27th day of October 1964.

(SEAL) Attest:

EDWARD J. BRENNER ERNEST W. SWIDER Attesting Officer Commissioner of Patents 

1. AN OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF OIL AND ALKALINE EARTH METAL SALT PREPARED BY CONEUTRALIZING WITH ALKALINE EARTH METAL BASE, ABOUT 0.5 TO 10 WT. PERCENT OF ABOUT 0.5 TO 10 WT. PERCENT OF PHENOL AND ABOUT 3 TO 35 WT. PERCENT OF LOW MOLECULAR WEIGHT MONOCARBOXYLIC ACID HAVING ABOUT 2 CARBON ATOMS PER MOLECULE, WHEREIN SAID PHENOL HAS THE FORMULA: 